A semiconductor device which inverts electric power by switching, amplifying, or rectifying is called a power semiconductor device. Power semiconductor devices primarily include bipolar transistors, thyristors, MOSFETs (Metal Oxide Silicon Field Effect Transistors), or IGBTs (Insulated-Gate Bipolar Transistors) as a switching element, or a pn junction diode, a pin diode (p-intrinsic-n Diode), or SBD (Shottky Barrier Diode) as a rectifying element.
IGBTs as a bipolar element can be operated at high speed due to their having a MOS gate, be driven with a large current with low loss, and have a large safety operation region with a high breakdown voltage and are used in various fields and have been actively developed. IGBTs, which are operated with the low loss, the large drive current, and the high breakdown voltage, can be widely applied while being operated at lower speeds than an operation speed of a MOSFET as a unipolar element. In such IGBT, an avalanche withstand value at which an element does not break down in an avalanche phenomenon during switching operation is considered as an important design item.
A semiconductor device with a high avalanche withstand amount is provided in the present embodiments.